2 * kernfs.h - pseudo filesystem decoupled from vfs locking
4 * This file is released under the GPLv2.
7 #ifndef __LINUX_KERNFS_H
8 #define __LINUX_KERNFS_H
10 #include <linux/kernel.h>
11 #include <linux/err.h>
12 #include <linux/list.h>
13 #include <linux/mutex.h>
18 struct vm_area_struct;
22 struct sysfs_open_file {
23 /* published fields */
24 struct sysfs_dirent *sd;
27 /* private fields, do not use outside kernfs proper */
30 struct list_head list;
33 const struct vm_operations_struct *vm_ops;
38 * Read is handled by either seq_file or raw_read().
40 * If seq_show() is present, seq_file path is active. The behavior
41 * is equivalent to single_open(). @sf->private points to the
42 * associated sysfs_open_file.
44 * read() is bounced through kernel buffer and a read larger than
45 * PAGE_SIZE results in partial operation of PAGE_SIZE.
47 int (*seq_show)(struct seq_file *sf, void *v);
49 ssize_t (*read)(struct sysfs_open_file *of, char *buf, size_t bytes,
53 * write() is bounced through kernel buffer and a write larger than
54 * PAGE_SIZE results in partial operation of PAGE_SIZE.
56 ssize_t (*write)(struct sysfs_open_file *of, char *buf, size_t bytes,
59 int (*mmap)(struct sysfs_open_file *of, struct vm_area_struct *vma);
64 struct sysfs_dirent *kernfs_create_dir_ns(struct sysfs_dirent *parent,
65 const char *name, void *priv,
67 struct sysfs_dirent *kernfs_create_link(struct sysfs_dirent *parent,
69 struct sysfs_dirent *target);
70 void kernfs_remove(struct sysfs_dirent *sd);
71 int kernfs_remove_by_name_ns(struct sysfs_dirent *parent, const char *name,
73 int kernfs_rename_ns(struct sysfs_dirent *sd, struct sysfs_dirent *new_parent,
74 const char *new_name, const void *new_ns);
75 void kernfs_enable_ns(struct sysfs_dirent *sd);
76 int kernfs_setattr(struct sysfs_dirent *sd, const struct iattr *iattr);
78 #else /* CONFIG_SYSFS */
80 static inline struct sysfs_dirent *
81 kernfs_create_dir_ns(struct sysfs_dirent *parent, const char *name, void *priv,
83 { return ERR_PTR(-ENOSYS); }
85 static inline struct sysfs_dirent *
86 kernfs_create_link(struct sysfs_dirent *parent, const char *name,
87 struct sysfs_dirent *target)
88 { return ERR_PTR(-ENOSYS); }
90 static inline void kernfs_remove(struct sysfs_dirent *sd) { }
92 static inline int kernfs_remove_by_name_ns(struct sysfs_dirent *parent,
93 const char *name, const void *ns)
96 static inline int kernfs_rename_ns(struct sysfs_dirent *sd,
97 struct sysfs_dirent *new_parent,
98 const char *new_name, const void *new_ns)
101 static inline void kernfs_enable_ns(struct sysfs_dirent *sd) { }
103 static inline int kernfs_setattr(struct sysfs_dirent *sd,
104 const struct iattr *iattr)
107 #endif /* CONFIG_SYSFS */
109 static inline struct sysfs_dirent *
110 kernfs_create_dir(struct sysfs_dirent *parent, const char *name, void *priv)
112 return kernfs_create_dir_ns(parent, name, priv, NULL);
115 static inline int kernfs_remove_by_name(struct sysfs_dirent *parent,
118 return kernfs_remove_by_name_ns(parent, name, NULL);
121 #endif /* __LINUX_KERNFS_H */